Superinsulation is an approach to building design, construction, and retrofitting that dramatically reduces heat loss (and gain) by using much higher levels of insulation and airtight than usual. Superinsulation is one of the ancestors of the passive house approach.
Video Superinsulation
Definisi
There is no universally agreed superinsulation definition, but superinsulated buildings usually include:
- Very high insulation level, usually R-40 wall (RSI-7) and R-60 roof (RSI-10.6), corresponds to SI values ​​of 0.15 and 0.1 W/(mÃ, ²Ã, K) respectively)
- Details to ensure continuity of insulation where the wall meets the roof, foundations, and other walls
- Airtight construction, especially around doors and windows to prevent air infiltration encouraging incoming or outgoing heat
- heat recovery ventilation system to provide fresh air
- No large windows are facing a certain direction
- Much smaller than conventional heating systems, sometimes just a small backup heater
Nisson & amp; Dutt (1985) states that a house may be described as "superinsulated" if the heating cost of space is lower than the cost of heating water.
Maps Superinsulation
Theory
A superinsulated house is intended to reduce the need for very significant heating and may even be heated primarily by an intrinsic heat source (waste heat generated by equipment and heat of the occupant's body) with a very small amount of reserve heat. It has been proven to work even in very cold climates but requires close attention to construction details in addition to isolation (see IEA Solar Heating & Cooling Task Implementation Agreement 13).
History
The term "superinsulation" was coined by Wayne Schick at the University of Illinois at Urbana-Champaign. In 1976 he was part of a team that developed a design called the "Lo-Cal" home, using computer simulations based on the Madison, Wisconsin climate. Some homes, duplexes and condos based on Lo-Cal principles were built in Champaign-Urbana, Illinois in the 1970s.
In 1977, "Saskatchewan House" was built in Regina, Saskatchewan, by a group of several Canadian government agencies. It was the first house to openly show the superinsulation value and generate a lot of attention. Initially included some solar panels that were evacuated experimentally, but they were not needed and then removed. The house was heated mainly by waste heat from equipment and occupants.
In 1977, "Leger House" was built by Eugene Leger, in East Pepperell, Massachusetts. It has a more conventional appearance than "Saskatchewan House", and also receives extensive publicity.
The publicity of "Saskatchewan House" and "Leger House" influenced other builders, and many superinsulated homes were built over the next few years. These houses also affected Wolfgang Feist when he developed the Passivhaus standard.
Retrofits
It is possible, and more desirable, to retrofit superinsulation into existing homes or buildings. The easiest way is to add a continuous rigid exterior insulating layer, and sometimes by building a new exterior wall that allows more space for insulation. A steam barrier can be installed outside the original frame but may not be needed. An improved continuous air barrier is almost always an added value, as older homes tend to leak, and such air barriers can be important for energy saving and endurance. Care should be taken when adding vapor barriers as it can reduce incidental moisture drying, or even cause summer (in climates with humid summers) of interstitial condensation and consequent mold and mold. This can cause health problems for occupants and damage existing structures. Many builders in northern Canada use a simple 1/3 to 2/3 approach, placing a vapor barrier no more than 1/3 of the R value of an isolated part of the wall. This method generally applies to interior walls that have little or no steam resistance (eg they use fibrous insulation) and control condensation of air leakage as well as condensation of vapor diffusion. This approach will ensure that condensation does not occur on or inside the vapor barrier during cold weather. The 1/3: 2/3 rule will ensure that the vapor barrier temperature will not fall below the dew point temperature of the interior air, and will minimize the possibility of cold weather condensation problems. For example, with an internal room temperature of 20 ° C (68 ° F), the vapor barrier will only reach 7.3 ° C (45 ° F) when the outside temperature is at -18 ° C (-1 ° F )). Temperature of indoor air dew is more likely to be around 0 Ã, Â ° C (32 Ã, Â ° F) when it is cold outside, much lower than the predicted vapor barrier temperature, and therefore 1/3: 2/3 rule quite conservative. For temperatures that do not often experience -18 Â ° C, the 1/3: 2/3 rule should be changed to 40: 60% or 50:50. Since the temperature of the internal dewpoints is an important basis for the rule, buildings with high interior humidity during cold weather (eg museums, swimming pools, airtight underhand or poorly ventilated) may require different rules, such as buildings with dry interior environments (such as high-ventilated buildings, warehouses). 2009 International Residential Code (IRC) embodies more sophisticated rules to guide the selection of insulation on new home exteriors, which can be applied when retrofitting older homes.
Steam permeable building wrappings on the outside of the original wall help keep the wind away, but allow the wall assembly to dry outward. Asphalt felt and other products such as permeable polymer based products are available for this purpose, and are usually duplicated as Air Resistant Barrier/drainage planes as well.
Interior retrofits are possible where the owner wants to retain the old exterior siding, or where the regressive requirements leave no room for exterior retrofit. Sealing air barrier is more difficult and the continuity of thermal insulation is disturbed (due to multiple partitions, floors, and service penetration), the original wall assembly becomes colder in cold weather (and hence more susceptible to condensation and slower dry), occupants exposed to major disturbances, and abandoned homes with fewer interior spaces. Another approach is to use the above-mentioned 1/3 to 2/3 method - that is, install a steam retarder inside the existing wall (if nothing already exists) and add insulation and support structures to the inside. In this way, utilities (electricity, telephone, cable, and pipe) can be added in this new wall space without breaking through the air barrier. Polyethylene vapor resistance is risky except in very cold climates, as they limit the ability of the wall to dry to the interior. This approach also limits the amount of interior insulation that can be added to a small amount (eg, only R6 can be added to a 2x4 R12 wall).
Cost and benefits
In new construction, the cost of extra insulation and wall framing can be offset by not requiring a dedicated central heating system. In homes with multiple rooms, more than one floor, air-conditioning or large, central furnaces are often justified or required to ensure a fairly uniform temperature. Small stoves are not too expensive and some need air ducts for every room is almost always necessary to provide air vent in any case. When peak demand and annual energy use are low, costly, sophisticated and expensive central heating systems are not often necessary. Therefore, even electric resistance heaters can be used. Electric heating is usually only used on the coldest winter evenings when overall electricity demand is low. Other forms of backup heating are widely used, such as wood pellets, wood stoves, natural gas boilers or even stoves. The cost of superinsulation retrofit must be balanced with the cost of future heating fuel (which can be expected to fluctuate year by year due to supply problems, natural disasters or geopolitical events), the desire to reduce pollution from heating buildings, or the desire to provide extraordinary thermal comfort.
During power outage, the superinsulated house remains warm longer because the heat loss is much less than normal, but the thermal storage capacity of the structural material and its contents is the same. Bad weather can hamper efforts to recover energy, leading to blackouts for a week or more. When there is a shortage of continuous power supply (either for direct heat, or to operate a gas-fired furnace), conventional homes cool down rapidly during, and may be at greater risk of costly damage from frozen water pipes. Residents who use additional heating methods without proper treatment during the episode, or at other times, may be at risk of fire or carbon monoxide poisoning.
See also
The first superinsulated house uses standard stud-wall construction, but other building techniques can be used:
- Isolation of concrete form (ICF)
- Straw bale construction
- Structural insulation panel (SIP)
- Sheltered from Earth
- Earthship
- Energy conservation
- Passive house
- Building insulation
- Building insulation materials
- Buildings without energy
- Seasonal thermal energy storage (STES)
Note
References
External links
- Rule 10-20-40-60 Joe Lstiburek
- Optimizing Shell Building with Superinsulation
- Super-Isolated House Plan (Earth News)
- Why Superinsulation is so important in building passive home standards
- Images and specifications of 12 different superinsulated wall assemblies
- Superinsulation retrofit from Sears Roebuck 1915 house
- "Sources on Superinsulation History". solarhousehistory.com.
Source of the article : Wikipedia
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